Field of the Invention
The present invention relates to a liquid crystal display.
Discussion of the Background
Liquid crystal displays (LCDs) are one of the most widely used flat panel displays, and an LCD includes a pair of panels provided with field-generating electrodes, such as pixel electrodes and a common electrode, and a liquid crystal (LC) layer disposed between the two panels. The LCD displays images when voltages are applied to the field-generating electrodes to generate an electric field in the LC layer, which determines the orientations of LC molecules therein, thereby adjusting the polarization of light incident thereto.
Among LCDs, a vertical alignment (VA) mode LCD, in which LC molecules are aligned such that the long axes of the LC molecules are perpendicular to the panels in the absence of an electric field, has been developed.
In a VA mode LCD, a wide viewing angle can be realized due to cutouts, such as slits in the field-generating electrodes and protrusions on the field-generating electrodes. Since the cutouts and protrusions may determine the tilt directions of the LC molecules, the tilt directions may be distributed in several directions using the cutouts and protrusions, thereby widening the reference viewing angle.
Also, a method for pretilting LC molecules in the absence of an electric field has been developed to improve the response speed of the LC molecules while realizing a wide viewing angle. For the LC molecules to pretilt in various directions, alignment layers having various alignment directions may be used. Alternatively, the LC layer may be subjected to an electric field and a thermal or light-hardened material may be added. Then light may be irradiated onto the LC layer to harden the thermal or light-hardening material, thereby pretilting the LC molecules.
However, the VA mode liquid crystal display may have lower side visibility compared with front visibility. To improve the side visibility, one pixel may be divided into two subpixels and different voltages may be applied to the subpixels.